From aecaffc55dd763c34f61937b2047f0aaaeb4e6fc Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Thu, 6 Aug 2020 11:32:33 +0200
Subject: [PATCH 66/74] libfdisk: fix fdisk_reread_changes() for extended
 partitions

Linux kernel assumes only 1KiB extended partition to avoid overlapping
with nested logical partitions. We need to follow this rule for
BLKPG_ADD_PARTITION.

Addresses: https://github.com/karelzak/util-linux/issues/1112
Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=2041498
Upstream: http://github.com/util-linux/util-linux/commit/33f50706fd7c1c5e53f8f355f12b685c6935f5a4
Signed-off-by: Karel Zak <kzak@redhat.com>
---
 libfdisk/src/context.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/libfdisk/src/context.c b/libfdisk/src/context.c
index fe7eb9e7e..114101980 100644
--- a/libfdisk/src/context.c
+++ b/libfdisk/src/context.c
@@ -867,10 +867,21 @@ int fdisk_reread_changes(struct fdisk_context *cxt, struct fdisk_table *org)
 		}
 	}
 	for (i = 0; i < nadds; i++) {
+		uint64_t sz;
+
 		pa = add[i];
+		sz = pa->size * ssf;
+
 		DBG(PART, ul_debugobj(pa, "#%zu calling BLKPG_ADD_PARTITION", pa->partno));
+
+		if (fdisk_is_label(cxt, DOS) && fdisk_partition_is_container(pa))
+			/* Let's follow the Linux kernel and reduce
+                         * DOS extended partition to 1 or 2 sectors.
+			 */
+			sz = min(sz, (uint64_t) 2);
+
 		if (partx_add_partition(cxt->dev_fd, pa->partno + 1,
-					pa->start * ssf, pa->size * ssf) != 0) {
+					pa->start * ssf, sz) != 0) {
 			fdisk_warn(cxt, _("Failed to add partition %zu to system"), pa->partno + 1);
 			err++;
 		}
-- 
2.31.1